Just about nine months ago, on June 28th, the Tau Manifesto, on Tau day, was launched. You may know that it is Pi day and you might have celebrated with some freshly baked Pi. That’s great. However, did you ever stop to wonder: what if radians made more sense? What? Oh yes.

March 14, or 3/14, is known as Ã¢â‚¬Å“Pi DayÃ¢â‚¬Â because of its resemblance to the first three digits in the decimal expansion of Ãâ‚¬ (pi), which is defined as the ratio of a circleÃ¢â‚¬â„¢s circumference to its diameter.

As “the circle constant”, Ãâ‚¬ is the object of virtually unlimited adulation, so you are probably under the impression that Ãâ‚¬ is a particularly important number. I am sorry to report that you have been misinformed.

The true circle constant is the ratio of a circleÃ¢â‚¬â„¢s circumference to its radius, not to its diameter. This number, called Ãâ€ž (tau), is equal to 2Ãâ‚¬, so Ãâ‚¬ is 12Ãâ€žÃ¢â‚¬â€and March 14 is thus Half Tau Day. (Of course, June 28, or 6/28, is Tau Day itself.) Although it is of great historical importance, the mathematical significance of Ãâ‚¬ is simply that it is one-half Ãâ€ž.

But how can this be? What about trigonometry? What about EulerÃ¢â‚¬â„¢s identity? What about Ãâ‚¬r2? Can Ãâ‚¬ really be wrong? All your questions and more are answered here, in an article called The Tau Manifesto.

Why is this at all important? I’ve always disliked radians. The biggest problem was their lack of proportion on the unit circle. A single revolution around the circle should be a single unit. In terms of Pi however, it is not. In terms of Tau it is.

I’ve even told my fellow mathematically inclined friends about Tau. After being slightly confused, they saw the revolutionary light. You need to read The Tau Manifesto to truly understand the importance of a logical constant equaling 2Pi.